From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753659AbbCaIxO (ORCPT ); Tue, 31 Mar 2015 04:53:14 -0400 Received: from foss.arm.com ([217.140.101.70]:34729 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751008AbbCaIxL (ORCPT ); Tue, 31 Mar 2015 04:53:11 -0400 From: Juri Lelli To: peterz@infradead.org Cc: linux-kernel@vger.kernel.org, Juri Lelli , Ingo Molnar , Kirill Tkhai , Juri Lelli Subject: [PATCH] sched/deadline: always enqueue on previous rq when dl_task_timer fires Date: Tue, 31 Mar 2015 09:53:36 +0100 Message-Id: <1427792017-7356-1-git-send-email-juri.lelli@arm.com> X-Mailer: git-send-email 2.2.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org dl_task_timer() may fire on a different rq from where a task was removed after throttling. Since the call path is: dl_task_timer() -> enqueue_task_dl() -> enqueue_dl_entity() -> replenish_dl_entity() and replenish_dl_entity() uses dl_se's rq, we can't use current's rq in dl_task_timer(), but we need to lock the task's previous one. Signed-off-by: Juri Lelli Tested-by: Wanpeng Li Acked-by: Kirill Tkhai Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Kirill Tkhai Cc: Juri Lelli Cc: linux-kernel@vger.kernel.org Fixes: 3960c8c0c789 ("sched: Make dl_task_time() use task_rq_lock()") --- kernel/sched/deadline.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 3fa8fa6..f670cbb 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -514,7 +514,7 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer) unsigned long flags; struct rq *rq; - rq = task_rq_lock(current, &flags); + rq = task_rq_lock(p, &flags); /* * We need to take care of several possible races here: @@ -569,7 +569,7 @@ static enum hrtimer_restart dl_task_timer(struct hrtimer *timer) push_dl_task(rq); #endif unlock: - task_rq_unlock(rq, current, &flags); + task_rq_unlock(rq, p, &flags); return HRTIMER_NORESTART; } -- 2.2.2